Thor Industries Inc. announced today (Nov. 10) that Wade F. B. Thompson is ill and has relinquished his duties as chairman of the board, president and CEO.

Effective immediately, Peter B. Orthwein, vice chairman, co-founder and a director of Thor, will serve in that capacity.

Orthwein, 64, has served as a director of Thor since its founding in 1980 and vice chairman since 1986.

Thompson, 69, has been president and CEO and a director since the company’s founding in 1980. He also owns 28.4% of Thor stock, according to a regulatory filing last week.

Thor, based in Jackson Center, Ohio, has been hit hard by the recession, which undercut demand for RVs. In the fiscal year ended July 31, the company’s sales tumbled 42% and profit fell to $17.1 million from $92.7 million the year before, according to Associated Press.

Last week, the company said sales in the quarter ended Oct. 31 were up 14% from a year ago, and Thompson said the company’s backlog had grown during months when it usually declines, which he said showed strength in towable vehicles and motorhomes.

Thompson and Orthwein founded Thor Industries with the acquisition of Airstream, an iconic brand that had hit a rough patch of road in the late 1970s. Within two years, Thompson and Orthwein cut costs and returned Airstream to profitability, then began a series of acquisitons which made Thor the largest RV company in the country.

After a slump that began in late 2007, the shares have rallied recently and are trading near their 52-week high of $32.98.